Device-to-device (D2D) technology is getting attraction because of the ability to offer new services, improve system throughput, and offer a better user experience. For example, D2D can be used for Public Safety (PS) services. Other potential use cases for D2D have been identified by 3GPP SA WG1 in 3GPP TR 22.803 V12.0.0 (2012-12), which is incorporated herein by reference in its entirety.
D2D discovery and direct communication allows user equipments (UEs) in proximity to communicate with each other directly. Identified areas of application include services related to commercial services and public safety that would be of interest to operators and users.
Long Term Evolution (LTE) device-to-device proximity services may be evaluated as follows in terms of the connectivity and direct communications requirements in different wireless coverage regions.